Set of floor panels for forming a floor covering

ABSTRACT

A set of floor panels for forming a floor covering, which comprises at least two floor panels, which each comprise an edge provided with a coupling part, wherein the coupling parts are configured such that they allow realizing a coupled condition between the floor panels, by means of a substantially straight-lined coupling movement of the one floor panel in respect to the other floor panel, according to a direction substantially perpendicular to an installation plane; and wherein the coupling parts are configured such that they, in the coupled condition, realize a tensioning force pressing the coupled edges towards each other.

BACKGROUND 1. Field of the Disclosure

The present invention relates to a set of floor panels, which issuitable for forming a floor covering.

More particularly, the present invention relates to a set of floorpanels for forming a floor covering, of the type which comprises atleast two floor panels, which each comprise an upper side, a lower side,and a core extending between the upper and lower sides, and which eachcomprise an edge provided with a coupling part, wherein the couplingparts are configured such that they allow realizing a coupled conditionbetween the floor panels by means of a substantially straight couplingmovement of the one floor panel in respect to the other floor panel,according to a direction substantially perpendicular to an installationplane; wherein the coupling parts in the coupled condition effect alocking in the direction parallel to the installation plane andperpendicular to the edges, as well as a locking in the directionperpendicular to the installation plane; wherein the coupling part ofthe one floor panel is made as a hook-shaped part directed towards thelower side of the floor panel, herein below denominated locking hook,and the coupling part of the other floor panel is made as a hook-shapedpart directed towards the upper side of the floor panel, herein belowdenominated receiving hook; wherein the hook-shaped parts substantiallyare manufactured from the material of the core of the floor panels andsubstantially are made in one piece therewith; wherein the locking hookcomprises a lip which is provided with a locking part extending towardsthe lower side of the floor panel, and the receiving hook comprises alip which is provided with a locking part extending towards the upperside of the floor panel; and wherein the locking parts, in the coupledcondition, cooperate in such a manner that they effect at least theaforementioned locking in the direction parallel to the installationplane and perpendicular to the edges.

2. Related Art

From, amongst others, documents WO 2010/015516 A2, WO 2011/028171 A1, WO2012/084604 A1 and WO 2012/101171 A1, such sets of floor panels areknown, wherein the locking in the direction perpendicular to theinstallation plane is effected without the assistance of a separateinsertion piece or insert.

Documents WO 2006/043893 A1, WO 2008/068245 A1 and WO 2009/066153 A2also form a disclosure of such sets of floor panels, wherein the lockingin the direction perpendicular to the installation plane is effected bymeans of a separate insertion piece or insert.

A general problem with the known sets of floor panels as described aboveis the risk of moisture or dust penetrating between the coupled edges ofthe floor panels.

In order to remedy this problem, the already above-mentioned WO '153describes that the floor panels described therein can be realized with aso-called “pretension”, which means that the edges in the coupledcondition are pressed towards each other by means of a tensioning force.

According to WO '153, the tensioning force can be realized in that thelip of the receiving hook, in the coupled condition, is elasticallybent, wherein the principle known from WO 97/47834 A1 can be applied.

In that the coupled edges are pressed towards each other, the formationof gaps in the coupled condition is counteracted and thereby the risk ofmoisture or dust penetrating between the coupled edges is reduced.

However, there is a risk that difficulties will be experienced whencoupling the floor panels which are provided with pretension. In orderto be able to realize the pretension, the profile shapes or the contoursof the coupling parts in fact have to be made overlapping, and thus theyare not complementary fitting. Moreover, the coupling movement can becomplicated further by the almost unavoidable tolerances of theperpendicularity of the sides of the floor panels.

Therefore, the coupling parts in practice mostly are configured suchthat they fit into each other with a certain play, which in its turnthen entrains the risk of moisture and dust penetrating between thecoupled edges. However, the play provides for that the floor panels canbe coupled easily and that the tolerances of the perpendicularity of thesides of the floor panels can be compensated.

WO 2007/141605 (A2) as well describes that the floor panels describedtherein can be realized with a pretension, by means of an elasticbending of the lip of the receiving hook in the coupled condition, whichprovides for that the coupling parts are pressed towards each other.However, at least one of the hooks of WO '605 for the major part is madeas a separate insertion piece, which is made of a different materialthan the core of the floor panel to which the respective hook isbelonging. In that such insertion piece has to be provided, the floorpanels of WO '605 are not cheap.

SUMMARY

The present invention primarily aims at an alternative set of floorpanels for forming a floor covering, wherein according to variouspreferred embodiments solutions are offered to problems with the sets offloor panels of the state of the art.

To this aim, the invention, according to a first independent aspectthereof, relates to a set of floor panels for forming a floor covering,of the aforementioned type, with the characteristic that the couplingparts are configured such that they, in the coupled condition, realize atensioning force pressing the coupled edges towards each other, by meansof an elastic bending of the lip of the receiving hook; and that the lipof the receiving hook, in the coupled condition, in the directionperpendicular to the installation plane, shows a maximum bending of atmost 0.0625 times the overall thickness of the floor panel.

The inventor has found that a maximum bending of at most 0.0625 timesthe overall thickness of the floor panel allows effectivelycounteracting the forming of gaps between the coupled edges and in thismanner minimizing or even excluding the risk of penetrating moisture anddust. Therein, moreover it has become apparent that the floor panels,although they are provided with a pretension, still can be coupled toeach other in a smooth manner.

A particularly good balance between the extent of gap counteracting andthe smoothness of installation can be obtained when said maximum bendingis at most 0.05 times the overall thickness of the floor panel andpreferably is situated between 0.0065 and 0.025 times the overallthickness of the floor panel, wherein a value of approximately 0.0125times the overall thickness of the floor panel has proven ideal.

Herein, it is noted that the maximum bending of the respective lip hasto be understood as the maximum bending in respect to the restingcondition of the lip, i.e. in respect to the condition of the lip innot-coupled or not-installed condition of the floor panels.

The maximum bending can be obtained in a simple manner in the case thatthe elastic bending relates to a downward bending, wherein the term“downward” has to be interpreted relative in respect to the installationplane of the floor panels.

For example, this may relate to a downward bending, wherein the lip ofthe receiving hook partially is situated lower than a level defined bythe lower side of the floor panel to which the locking hook isbelonging.

The elastic bending preferably relates to a bending continuouslyincreasing in distal direction in respect to the receiving hook, whereinsaid maximum bending occurs at the distal end of the lip of thereceiving hook. As the mentioned maximum bending is achieved by means ofa continuously increasing bending, the advantage is obtained that aparticularly effective tensioning force can be realized without therebycreating an appreciable risk of breaking or damage. In fact, the load towhich the respective lip is subjected can be distributed over the lengthof the respective lip.

The herein above-mentioned advantages primarily will be apparent in thecase that the lip of the receiving hook is bent at least over 25%, andpreferably at least over 50% of its length, and still more when therespective lip is bent over at least 75% of its length.

It is also noted that the term “thickness” indicates the dimensionaccording to the direction perpendicular to the upper or lower side ofthe floor panel. In particular, by the overall thickness of the floorpanel the distance is indicated between the upper and lower sides of thefloor panel.

It is also noted that the term “length” has to be understood as thedimension according to the direction parallel to the upper or lower sideand perpendicular to the edges.

According to a second independent aspect thereof, the present inventionrelates to a set of floor panels for forming a floor covering, of theaforementioned type, with the characteristic that the coupling parts areconfigured such that they, in the coupled condition, realize atensioning force pressing the coupled edges towards each other, by meansof an elastic bending of the lip of the receiving hook; and that thecoupling parts are configured such that at least a portion of thelocking part extending towards the lower side of the floor panel fitsinto an opening defined between the portion extending towards the upperside of the floor panel and a proximal side of the receiving hook,without having to elastically bend the lip of the receiving hook to thisaim. Herein, by the term “opening” a recess or groove is meant which isprovided in the lip of the receiving hook, and in which the locking partof the locking hook directed towards the lower side of the floor panelbecomes seated in the coupled condition of the floor panels.

This configuration of the coupling parts offers the advantage that thesmoothness of installation of the floor panels can be guaranteedalthough they are provided with a pretension.

Moreover, the elastic bending of the lip of the receiving hook can beinitiated starting from an already partially engaged condition of thehook-shaped parts. Consequently, the risk of a difficult engagement ofthe hook-shaped parts, for example, as a result of the elasticdeformation of the respective lip, can be minimized or even excluded.

For example, the elastic bending is initiated by a mutual interaction ofproximal sides, more particularly locking surfaces, of the lockingparts.

According to an independent third aspect thereof, the present inventionrelates to a set of floor panels for forming a floor covering, of theaforementioned type, with the characteristic that the coupling parts areconfigured such that they, in the coupled condition, realize atensioning force pressing the coupled edges towards each other, by meansof an elastic bending of the lip of the receiving hook; and that the lipof the receiving hook has a minimum thickness which is at least ⅕ timesand at most ⅓ of the overall thickness of the floor panel; and that thelength of the lip of the receiving hook, measured between the verticalclosing surface and the distal end of the lip, is at least 1 times andat most 3/2 times the overall thickness of the floor panel. Herein, theterm “vertical closing surface” has to be understood as the verticalsurface defined there, where the upper edges of the floor panels adjoineach other. In other words, this is the vertical surface which isdefined there, where a distal side of the locking hook adjoins against aproximal side of the receiving hook.

The realization of the respective lip offers the advantage that, on theone hand, it can be provided with elastic features in order to undergothe elastic bending, and, on the other hand, can be provided with therequired strength and stability, such that the forming of gaps can becounteracted in an effective manner and the risk of breaking or damagecan be minimized.

A particularly good balance between elasticity and stability can beobtained when said minimum thickness is at most 0.3 times the overallthickness of the floor panel, wherein it has proven ideal when saidminimum thickness is at most ¼ times the overall thickness of the floorpanel.

With the same aim, the herein above-defined length preferably is at most1.4 times the overall thickness of the floor panel, wherein said lengthmost preferably is at most 4/3 times the overall thickness of the floorpanel.

It is also noted that the term “length” has to be understood as thedimension according to the direction parallel to the upper or lower sideand perpendicular to the edges.

According to an independent fourth aspect thereof, the present inventionrelates to a set of floor panels for forming a floor covering, of theaforementioned type, with the characteristic that the coupling parts areconfigured such that they, in the coupled condition, realize atensioning force pressing the coupled edges towards each other, by meansof an elastic bending of the lip of the receiving hook; and that the lipof the receiving hook comprises a bridge part connected to the core ofthe floor panel, and an end part connected to the bridge part, to whichthe locking part extending towards the upper side of the floor panel isbelonging, wherein the bridge part comprises an upper side provided witha recess or groove, which recess, viewed according to the directionparallel to the upper or lower side of the floor panel and perpendicularto the edge, is situated at a distance from there, where the bridge partis connected to the core of the floor panel, and from there, where thebridge part is connected to the end part.

The recess offers the advantage that the lip of the receiving hook canbe provided with elastic features in order to allow the elastic bending,however, can be made relatively rigid or stable, such that, via thementioned tensioning force, it can effectively counteract the formationof gaps, without thereby being subjected to breaking or damage.

The mentioned advantages are particularly apparent in the case that thelip of the receiving hook has its minimum thickness there, where saidrecess is provided.

There, where the bridge part is connected to the core of the floorpanel, and there, where it is connected to the end part, the bridge partpreferably is made more rigid or thicker than there, where said recessis provided. In this manner, the risk of breaking or damage can beminimized, in particular there, where the load on the respective lip canbe highest.

It can be prevented that the elastically bent lip will break undernormal usage conditions, when the bridge part there, where it isconnected to the core of the floor panel, has a thickness which is atleast ⅕ times, and preferably at least ¼ times the overall thickness ofthe floor panel.

Moreover, the bent lip can be enabled to compensate external forces, towhich the locking part of the receiving hook can be subjected undernormal usage conditions, without damage, in the case that the bridgepart there, where it is connected to the end part, has a thickness whichis at least ⅕ times, and preferably at least ¼ times the overallthickness of the floor panel.

According to an independent fifth aspect thereof, the present inventionrelates to a set of floor panels for forming a floor covering, of theaforementioned type, with the characteristic that the coupling parts areconfigured such that they, in the coupled condition, realize atensioning force pressing the coupled edges towards each other; and thatthe coupling parts are configured such that they allow to uncouple thefloor panels, starting from the coupled condition, by means of arotational movement of the one floor panel around the other floor panel,around an axis parallel to the installation plane and the edges, whereinthe upper sides of the floor panels during said rotational movement aremoved towards each other.

The advantage is obtained that the floor panels, from the coupledcondition, in which the edges are pressed towards each other, can beuncoupled in a simple manner. Thus, the user is offered the opportunityof a simple de-installation of the floor panels coupled with tensioningforce.

The tensioning force preferably is realized by means of an elasticbending of the lip of the receiving hook.

The lip of the receiving hook preferably comprises a bridge partconnected to the core of the floor panel, and an end part connected tothe bridge part, to which end part the locking part extending towardsthe upper side of the floor panel is belonging. There, where the bridgepart is connected to the end part, it preferably has a thickness whichis at least ⅕ times and preferably at least ¼ times the overallthickness of the floor panel. That the bridge part there, where it isconnected to the end part, is made relatively thick, offers theadvantage that the proximal side, more particularly the locking surface,of the locking part extending towards the upper side of the floor panel,can be lifted, which facilitates the pivoting apart of the floor panels.

According to a sixth independent aspect thereof, the present inventionrelates to a floor panel for forming a floor covering, of theaforementioned type, with the characteristic that the coupling parts areconfigured such that they, in the coupled condition, realize atensioning force pressing the coupled edges towards each other, by meansof an elastic bending of the lip of the receiving hook; that each of thefloor panels comprises an edge adjacent to its aforementioned edge,herein below denominated adjacent edge, which is provided with acoupling part, wherein the coupling parts at the adjacent edges areconfigured such that they allow realizing a coupled condition betweenthe floor panels, wherein the coupling parts at the adjacent edges, incoupled condition, effect a locking in the direction parallel to theinstallation plane and perpendicular to the adjacent edges, as well as alocking in the direction perpendicular to the installation plane, andwherein the coupling parts at the adjacent edges are configured suchthat they, in coupled condition, realize a tensioning force which, bymeans of an elastic bending of a lip pertaining to the coupling parts ofthe adjacent edges, presses the adjoining coupled edges towards eachother; and that, in the coupled condition of a plurality of the floorpanels, the average degree of bending of the lip of the receiving hook,viewed over the length of the coupled edges, differs from the averagedegree of bending of the lip pertaining to the coupling parts of theadjacent edges, viewed over the length of the coupled adjacent edges.Herein, it is noted that the “length of the edges” here has to beunderstood as the dimension of these edges in the direction parallel tothe edges and the installation plane.

As the average bending of the respective lips is different, theadvantage is obtained that an additional degree of freedom is createdfor optimizing the features of the floor covering, for example, in thefield of water or dust resistance.

The inventor has found that it is particularly advantageous, in respectto the smoothness of installation, that the average degree of bending ofthe lip of the receiving hook is larger than the average degree ofbending of the lip pertaining to the coupling parts of the adjacentedges. Specific advantages thereof will be explained in more detail inthe detailed description.

The coupling parts at the adjacent edges preferably are configured suchthat they allow realizing the coupled condition between the floor panelsby means of a rotational movement of the one floor panel in respect tothe other floor panel, around an axis parallel to the installation planeand the adjacent edges, in such a manner that a plurality of the floorpanels can be coupled by means of a fold-down movement.

For example, the coupling parts at the adjacent edges can be realized asa tongue and a groove, wherein the groove is bordered by an upper lipand said lip pertaining to the coupling parts of the adjacent edges,herein below denominated lower lip, which lower lip preferably extendsbeyond the distal end of the upper lip. The tongue and the groove may beprovided with lock-up parts, which in coupled condition effect saidlocking in the direction parallel to the installation plane andperpendicular to the adjacent edges.

It is also noted that the characteristics of the herein above-describedsix aspects within the scope of the invention can be combined at choice,as far as they are not contradictory.

Herein below, preferred, as well as alternative and possible embodimentsof the present invention are described, which, as such or incombination, can be applied to the herein above-described six aspects,as far as they are not contradictory.

It is also noted that, if not stated otherwise, herein below by theterms “edges” and “coupling parts”, respectively the edges are meantwhich are provided with the coupling parts which are made in the form ofthe herein above-described hook-shaped parts, and the coupling parts aremeant which are made in the form of the herein above-describedhook-shaped parts.

The ease of installation of the floor panels provided with pretension ispromoted, in the case that the locking part extending towards the upperside of the floor panel defines a point situated most towards the upperside of the floor panel, which point is situated in the lower half ofthe floor panel. Moreover, such embodiment of the respective lockingpart facilitates the possibility of pivoting the floor panels out ofeach other in order to uncouple them.

It is beneficial for the strength and solidity of the lip of thereceiving hook when it comprises a bottom side which is free fromrecesses or grooves.

The locking in the direction perpendicular to the installation plane, atthe edges to which the hook-shaped parts are pertaining, preferably iseffected by means of locking elements, of which more particularly atleast one locking element is realized as a separate insertion piece orinsert. The advantage of such insertion piece is that the featuresthereof can be adapted, on the one hand, in order to couple the floorpanels in a smooth manner, irrespective of the overlapping embodiment ofthe coupling parts, and, on the other hand, to be able to provide for astrong vertical locking, separate from the material of which the actualfloor panel is manufactured.

Preferably, the insert is provided in a groove present in a distal sideof the locking hook. Such groove can be provided without any noteworthyweakening of the locking hook and, more important, without adisadvantageous influence on the stability or solidity of the lip of thereceiving hook and the tensioning force supplied by the lip.

However, the invention does not exclude that the insert is placed in agroove provided in a proximal side of the receiving hook. However, suchgroove can have a detrimental influence on the stability of the lip ofthe receiving hook and consequently on the tensioning force supplied bythe lip.

Preferably, the insert comprises an elastically bendable portion, which,during the coupling movement, performs a lateral movement and is broughtfrom a relaxed or initial condition towards a locking condition, inwhich the movable portion cooperates with the locking element at theother floor panel. The advantage of such elastically bendable portion isthat the elasticity thereof can be applied for promoting the coupling ofthe floor panels, irrespective the overlapping embodiment of thecontours of the coupling parts.

For example, the insert may comprise a pivotable blocking body, as knownas such from documents WO 2008/068245 A1 and WO 2013/102804 A2, orconsist of a displaceable tongue which is provided in a displacementgroove, as known as such from WO 2006/043893 A1.

In the locking condition, the aforementioned movable part can at leastbe partially tensioned, by which the movable part realizes a tensioningforce. That the movable part is tensioned in the coupled condition,offers the advantage that the contact of that part with the lockingelement on the other floor panel can be guaranteed. In this manner, agood locking in the direction perpendicular to the installation plane isobtained, and the risk of the occurrence of height differences betweenthe upper sides of the floor panels can be minimized.

The tensioning force supplied by the movable part and the tensioningforce supplied by the lip of the receiving hook preferably areconfigured such that the coupled edges are pressed towards each other.For example, the tensioning force supplied by the movable part comprisesat least a force component, which presses the coupled edges out of eachother, wherein this force component is smaller than the force componentof the tensioning force supplied by the lip of the receiving hook, whichpresses the coupled edges towards each other. In other words, theresultant of the tensioning forces provides for that the coupled edgesstill are pressed towards each other.

Herein, it is also noted that it has proven particularly advantageous torealize the insert as a coextruded strip, as known as such from WO2009/066153 A2. In fact, by means of coextrusion the insert can berealized such that it effects a strong vertical locking and also allowsa smooth installation, irrespective of the overlapping design of thecoupling parts.

However, it is noted that the present invention does not exclude thatthe vertical locking is effected without the assistance of an insertionpiece or insert, and that the herein above-mentioned locking elementsall are manufactured from the material of the core of the floor panelsand are made in one piece therewith.

On one distal side thereof, the locking part extending towards the upperside of the floor panel preferably is free from locking elements. Inparticular, in the coupled condition of the floor panels a room or spaceis formed between said distal side and the opposite edge. Hereby, theadvantage is obtained that the respective lip can be bent out easily, asby means of said space room is made for that.

Each of the aforementioned locking parts preferably is provided with alocking surface on a proximal side of the locking part, wherein thelocking surfaces in coupled condition cooperate such that they effect atleast the locking in the direction parallel to the installation planeand perpendicular to the edges. These locking surfaces preferably aremade of the material of the core of the floor panels and are made in onepiece therewith.

Although it is not excluded that the locking surfaces assist in thelocking in the direction perpendicular to the installation plane, theypreferably will not do this. The fact that they do not assist in thementioned locking, contributes to a smooth installation of the floorpanels which have to be coupled with a tensioning force.

For example, the locking surface of the locking part extending towardsthe upper side of the floor panel extends in distal direction towardsthe upper side of the floor panel.

The inventor has found that the ease of installation of the floor panelswhich have to be coupled with a tensioning force is promoted in the casethat the locking surfaces, in coupled condition, define a maximallyinclined tangent line, which at most forms an angle of 85 degrees with astraight line parallel to the installation plane, wherein the tangentline extends towards the upper side of the floor panel, in distaldirection in respect to the receiving hook. It has proven particularlyadvantageous when said angle is at most 80 degrees, wherein mostpreferably said hook is approximately 75 degrees.

Preferably, the coupling parts are configured such that they allowrealizing a coupled condition between the floor panels, by means of arotational movement of the one floor panel in respect to the other floorpanel, around an axis parallel to the installation plane andperpendicular to the edges. Such configuration of the coupling partsallows coupling a plurality of such floor panels to each other by meansof a fold-down movement, which movement shows the herein above-describedadvantages particularly well.

In view of the fact that the present invention allows minimizing therisk of penetrating moisture and dust, it is primarily applied in anadvantageous manner with floor panels, the core of which is at leastpartially composed of wood-based materials, such as MDF, HDF, or WoodPlastic Composite or WPC.

However, the invention can also be applied in an advantageous mannerwith floor panels which comprise a core based on synthetic material,wherein a variety of synthetic materials can be applied, such asthermoplastics, elastomers, polyesters and the like. A particular typeof synthetic material-based floor panels, wherein the invention can beapplied in an advantageous manner, are the so-called LVT floor panels.

The floor panels preferably have an overall thickness which is situatedbetween 4 and 15 mm. Such thickness allows realizing the floor panelsstill stable enough. Most preferably, the overall thickness is situatedbetween 5 and 12 mm, wherein an overall thickness of approximately 8 mmhas proven to be an ideal value for realizing the elastically bent lipdescribed herein above.

The floor panels of the present invention primarily relate to decorativefloor panels. Preferably, they relate to floor panels comprising a toplayer, wherein the top layer comprises at least a decor and atransparent wear layer.

BRIEF DESCRIPTION OF THE DRAWINGS

With the intention of better showing the characteristics of theinvention, herein below, as an example without any limitative character,some preferred embodiments are described, with reference to theaccompanying drawings, wherein:

FIG. 1 in top view represents a set of oblong rectangular floor panels,wherein the floor panels are in a not-coupled or not-installedcondition;

FIG. 2 represents a cross-section according to line II-II in FIG. 1;

FIG. 3 represents a cross-section according to line III-III in FIG. 1;

FIG. 4 represents how a plurality of the floor panels of FIG. 1 can becoupled to each other;

FIG. 5, in an enlarged view, represents the edges from FIG. 2, however,in the coupled condition of the floor panels;

FIG. 6 represents a step in the coupling movement of the edges at theshort sides of the floor panels from FIG. 1;

FIG. 7 represents how the floor panels from FIG. 1 can be uncoupled atthe edges of their short sides by means of a pivoting movement; and

FIGS. 8 through 11 represent alternatives to the embodiment of the edgesof the short sides of the floor panels from FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1, in top view, represents a set of floor panels 1A-1B for forminga floor covering, wherein the floor panels 1A-1B here are oblongrectangular and thus comprise a pair of short sides and a pair of longsides. The floor panels 1A-1B are represented in a not-coupled ornot-installed condition.

The opposite short sides of the floor panels 1A-1B form edges 2-3 whichare provided with coupling parts 4-5. Although here opposite edges 2-3of two floor panels 1A-1B are concerned, it is clear that these edges2-3 can also relate to edges of one and the same floor panel, which thenrelate to opposite edges of that floor panel.

The long sides of the floor panels 1A-1B form edges 6-7, which areprovided with coupling parts 8-9.

FIG. 2 represents a cross-section according to line II-II in FIG. 1.Thus, FIG. 2 represents a cross-section wherein the coupling parts 4-5on the short sides of the floor panels 1A-1B are visible.

The floor panels 1A-1B each comprise an upper side 10, a lower side 11,and a core 12 extending between the upper and lower sides 10-11.

The floor panels 1A-1B relate to decorative floor panels, which comprisea top layer 43, wherein the top layer comprises at least a decor and atransparent wear layer.

The coupling part 4 of the one floor panel 1A is realized as ahook-shaped part 13 directed towards the lower side 11 of the floorpanel 1A, herein below denominated looking hook 13.

The coupling part 5 of the other floor panel 1B is realized as ahook-shaped part 14 directed towards the upper side 10 of the floorpanel 1B, herein below denominated receiving hook 14.

The hook-shaped parts 13-14 substantially are made from the material ofthe core 12 of the floor panels 1A-1B and substantially are made in onepiece therewith. Here, the hook-shaped parts 13-14 even are madeentirely from the material of the core 12, and in one piece therewith,with the exception of the insertion piece 19. To this aim, thehook-shaped parts 13-14 can be manufactured, for example, from thematerial of the core 12 by means of milling treatments, which is aneconomically advantageous and efficient manner of manufacturing thehook-shaped parts 13-14.

The locking hook 13 comprises a lip 15 which is provided with a lockingpart 16 extending towards the lower side 11 of the floor panel 1A.

The receiving hook 14 comprises a lip 17 which is provided with alocking part 18 extending towards the upper side 10 of the floor panel1B.

As illustrated by means of the coupling part 4 represented in dottedline, the coupling parts 4-5 are configured such that they allowrealizing a coupled condition between the floor panels 1A-1B, by meansof a substantially straight coupling movement M of the one floor panel1A in respect to the other floor panel 1B, according to a directionsubstantially perpendicular to an installation plane.

More particularly, the coupling parts 4-5 here are configured such thatthey also allow realizing a coupled condition between the floor panels1A-1B, by means of a rotational movement of the one floor panel 1A inrespect to the other floor panel 1B, around an axis parallel to theinstallation plane and perpendicular to the edges 2-3, in order to beable to perform the fold-down movement, which will be described ingreater detail in respect to FIG. 4.

In the coupled condition of the floor panels 1A-1B, which is illustratedin greater detail in FIG. 5, the coupling parts 4-5 effect a locking inthe direction H parallel to the installation plane and perpendicular tothe aforementioned edges 2-3, as well as a locking in the direction Vperpendicular to the installation plane.

Here, the locking parts 16 and 18 perform the locking in the direction Hparallel to the installation plane and perpendicular to theaforementioned edges 2-3.

The locking in the direction V perpendicular to the installation planeis effected by means of locking elements 19-20. The locking element 19here is realized as a separate insertion piece or insert, as known assuch from, for example, the herein above-mentioned WO '804.

The insert 19 here is provided in a groove 26, which is present in adistal side 21 of the locking hook 13. This offers the advantage thatsuch groove 26 does not have to be provided in the receiving hook 14,which then as a result thereof can be made strong and can rendersufficient stability to the lip 17.

However, it is not excluded that such insert 19 is provided in a groovewhich is present in a proximal side 23 of the receiving hook 14, whichthen preferably, instead of an upward-directed part 27, comprises adownward-directed part.

The part 27 is elastically movable, for example, by elastic bendingand/or compression, and during the coupling movement performs a lateralmovement, illustrated in greater detail in FIG. 6.

It is clear that here, and also in general, by the term “lateralmovement” a sideward movement is meant which has at least a movementcomponent in the direction parallel to the installation plane andperpendicular to the edges 2-3.

It should be noted that the part 27 here primarily, starting from arelaxed or initial condition, will perform a movement in the directiontowards the floor panel 1A, after which the part 27 subsequently will atleast partially relaxate towards a locking condition and herein willmove in the direction towards the floor panel 1B.

In the locking condition, the part 27 works in conjunction with thelocking element 20 at the other floor panel 20, shown in more detail inFIG. 5. Preferably, the part 27 relaxates only partially, as a result ofwhich it is at least partially tensioned in the locking condition andrealizes a tensioning force.

The insert 19 here is provided in the groove 26 by means of anattachment part 28, which can be clamped in this groove 26, for example,in that the part 28 is made not precisely fitting with the groove 26.

Here, the attachment part 28 more particularly is connected to themovable part 27 by means of a connection part 29.

More particularly, the insert 19 here is made as a coextruded strip,wherein the connection part 29 is manufactured of a softer or moreelastic material than the material of the parts 27 and 28, whichprinciple is known as such from, for example, the herein above-mentionedWO '153.

The lip 17 of the receiving hook 14 comprises a bridge part 37 connectedto the core 12 of the floor panel 1B, and an end part 38 connected tothe bridge part 37, to which end part the locking part 18 extendingtowards the upper side of the floor panel is belonging.

The bridge part 37 comprises an upper side provided with a recess 39.The recess 39, viewed according to the direction parallel to the upperor lower side 10-11 of the floor panel 1B and perpendicular to the edge3, is situated at a distance from there, where the bridge part 37 isconnected to the core 12 of the floor panel 1B, and from there, wherethe bridge part 37 is connected to the end part 38.

There, where the recess 39 is provided, the lip 17 has its minimumthickness D1, which preferably is at least ⅕ times and at most ⅓ timesthe overall thickness of the floor panel 1B. More particularly, theminimum thickness D1 here is at most ¼ times the overall thickness T ofthe floor panel 1B.

There, where the bridge part 37 is connected to the core 12 of the floorpanel 1B and there, where it is connected to the end part 38, it is mademore rigid or thicker than there, where the aforementioned recess 39 isprovided.

There, where the bridge part 37 is connected to the core 12, said bridgepart has a thickness D2 which is at least ⅕ times and preferably atleast ¼ times the overall thickness T of the floor panel 1B.

There, where the bridge part 37 is connected to the end part 38, saidbridge part has a thickness D3 which is at least ⅕ times and preferablyat least ¼ times the overall thickness T of the floor panel 1B.

That the bridge part 37 is made more rigid or thicker in the specificzones offers the advantage that the lip 17 is strong and can withstandpossible loads which it is subjected to, in particular in the zones.Moreover, the additional advantage is obtained that, in that the bridgepart 37 there, where it is connected to the end part 38, is madethicker, the locking surface 42 can be lifted, i.e. can be broughttowards a higher or more upward position, which promotes the smoothpivoting apart of the floor panels, illustrated in more detail in FIG.7.

The length L of the lip 17, measured between the vertical closingsurface VS and the distal end of the lip 17, is at least 1 time and atmost 3/2 times the overall thickness T of the floor panel 1B. Inparticular, the length L here is at most 4/3 times the overall thicknessT of the floor panel 1B.

The lip 17 of the receiving hook 14 comprises a lower side which is freefrom recesses or grooves, or weakened parts in general.

The locking part 18 defines a point P situated most towards the upperside 10 of the floor panel 1B, which point is located in the lower halfof the floor panel 1B. Such rather low designed locking part 18, amongstothers, offers the advantage that the pivoting apart of the floor panels1A-1B, illustrated in greater detail in FIG. 7, can be performed in asmooth manner.

FIG. 3 represents a cross-section according to line III-III in FIG. 1.Thus, here a cross-section is represented wherein the coupling parts 8-9on the long sides of the floor panels 1B are visible.

More particularly, the coupling parts 8-9 are realized as a tongue 30and a groove 31, respectively, wherein the groove 31 is bordered by anupper lip 32 and a lower lip 33, which lower lip 33 extends beyond thedistal end of the upper lip 32. The tongue 30 and the groove 31 areprovided with lock-up parts 34-35. In the coupled condition, they effectthe locking in the direction parallel to the installation plane andperpendicular to the edges 6-7.

As illustrated by the coupling part 8 represented in dotted line, thecoupling parts 8-9 are configured such that they allow realizing thecoupled condition between the floor panels 1A-1B, by means of arotational movement W of the one floor panel 1A in respect to the otherfloor panel 1B, according to a direction parallel to the installationplane and the edges 6-7.

Locking tongue and groove connections, such as those described hereinabove in respect to FIG. 3, are known as such, amongst others, from thealready mentioned herein above WO '834. From that document, it is knownthat such tongue and groove connections can be provided with pretension,i.e., that they, in the coupled condition, realize a tensioning forcepressing the coupled edges towards each other, for example, by means ofan elastic bending of the lower lip. Herein, it is noted that with suchlocking tongue and groove connections the pretension poses lessdifficulties in respect to the smoothness of installation, as they arecoupled by means of a pivoting or rotational movement, as describedherein above.

FIG. 4 represents how a plurality of the floor panels of FIG. 1 can becoupled by means of the so-called fold-down movement F, which as such isknown, amongst others, from WO 01/75247 A1 and, already mentioned hereinabove, WO '153.

As illustrated, the floor panel 1A is coupled at its long side to analready installed floor panel 1C from a preceding row, by means of apivoting movement, and at the same time is coupled at its short side toan already installed floor panel 1B from the same row, by means of thesame pivoting movement, which is also called a scissor movement.

It is noted that the fold-down movement in practice mostly is precededby a shifting movement of the floor panel 1A in respect to the floorpanel 1C, along the long sides of these floor panels 1A and 1C, whereinthe tongue during this shifting movement already is partially introducedinto the groove. Herein, the floor panel 1A is in an inclined condition.

The floor panels 1A-1B-1C here are represented as perfectly rectangularfloor panels, i.e. the short sides are perpendicular to the long sides.However, in practice this is not always the case. The standard EN 13329namely allows a deviation from perpendicularity of 0.2 mm over thelength of the side. It is clear that, due to this allowed deviation,performing the fold-down movement can be impeded; certainly at the sideswhere the coupling parts are realized in the form of hooks, here, thus,at the short sides, as these hooks due to the non-perpendicularity aredifficult to engage into each other, certainly in the case of hooks madeoverlapping, which is the case with pretension.

Now, the inventor has found that the smoothness of installation stillcan be guaranteed by means of the herein above-described measures andthe characteristics explained herein below in greater detail by means ofFIGS. 5 and 6.

FIG. 5 in an enlarged view represents the edges 2-3 from FIG. 2,however, in the coupled condition of the floor panels 1A-1B.

As made visible, the coupling parts 4-5 are configured such that they,in coupled condition, realize a tensioning force pressing the couplededges 2-3 towards each other, by means of an elastic bending of the lip17 of the receiving hook 14.

Herein, the lip 17 has a maximum bending VM of at most 0.0625 times theoverall thickness T of the floor panel 1B and this maximum bending hereis specifically equal to approximately 0.0125 times the overallthickness of the floor panel 1B. The inventor has found that suchmaximum bending VM allows realizing an effective tensioning force whichpresses the coupled edges 2-3 towards each other, and that thesmoothness of installation still can be guaranteed.

Herein, it is noted that the maximum bending VM of the lip 17 has to beunderstood as the maximum bending in respect to the resting condition ofthe lip 17, i.e. in respect to the condition of the lip 17 innot-coupled or not-installed condition of the floor panels 1A-1B, whichis represented in FIG. 2.

Here, the bending of the lip 17 relates to a downward bending, whereinthe lip 17 partially is situated lower than a level defined by the lowerside 11 of the floor panel 1A to which the locking hook 13 is belonging.

Moreover, the bending relates to a bending continuously increasing indistal direction in respect to the receiving hook. By this is meant thatthe lip 17 is bent out more and more in distal direction, which in FIG.5, for example, is represented by a more and more diminishing distancebetween the lower side of the lip 17 and the represented dotted line.The maximum bending VM then occurs at the distal end of the lip 17.

Such continuously increasing bending offers the advantage that thetension to which the lip 17 is subjected, can be spread over the lengthof this lip 17, and that an effective tensioning force can be realizedwithout a noteworthy risk of breaking or damage of the lip 17.

Thus, the lip 17 preferably is bent over at least 25%, and still betterover 50%, of its length.

As already described herein above, also the coupling parts 8-9 on thelong edges 6-7 can be provided with pretension, wherein a tensioningforce is created, which presses the coupled edges 6-7 towards eachother, for example, by means of an elastic bending of the lower lip 33.

Herein, it is preferred that the average degree of bending of the lip 17of the receiving hook 14, viewed over the length of the coupled edges2-3, is different from, and preferably larger than, the average degreeof bending of the lip 33 belonging to the coupling parts 8-9 of theadjacent edges 6-7, seen over the length of the coupled adjacent edges6-7.

It is noted that by the length of the edges here the dimension of theedges in a direction parallel to these edges is meant.

That the bending of the lip 17 is larger than the bending of the lip 33,offers the advantage that a smooth installation can be guaranteed,whereas the formation of gaps on the coupled edges 2-3 and 6-7 can becounteracted in an optimum manner, certainly with oblong rectangularfloor panels, such as those from FIG. 1.

On the one hand, it is advantageous that the bending of the lip 33 isrelatively small, and smaller than the bending of the lip 17, as thisallows smoothly performing the shifting movement of the floor panels 1Aand 1C along their long sides, already described herein above, prior tothe actual fold-down movement. On the other hand, it is advantageous toperform the bending of the lip 17 relatively large, and larger than thebending of the lip 33, as this results in a reduction of the risk of thepenetration of moisture or dust at the short sides of the coupled floorpanels 1A-1B.

As mentioned earlier in respect to FIG. 2, the movable part 27 of theinsert 19 in the locking position can be partially tensioned, such thatit realizes a tensioning force. This tensioning force provides for thatthe risk of height differences between the floor panels 1A-1B can beminimized or even excluded.

The tensioning force delivered by the part 27 here comprises at least aforce component which pushes the coupled edges 2-3 out of each other,however, wherein this force component is smaller than the forcecomponent of the tensioning force delivered by the lip 17, which pressesthe coupled edges towards each other, such that the coupled edges 2-3still are pressed towards each other.

At its distal side 22, the locking part 18 is free from lockingelements. In the coupled condition, even a room or space 40 is formedbetween the distal side 22 and the opposite edge 2. This space 40 offersroom for the elastic bending of the lip 17.

In the coupled condition, the locking surfaces 41-42 at the proximalsides 24-25 of the locking parts 16 and 18 cooperate such that theyeffect the locking in the direction H parallel to the installation planeand perpendicular to the edges 2-3. They are manufactured from thematerial of the core 12 of the floor panels 1A-1B and are made in onepiece therewith.

The locking surface 42 extends in distal direction towards the upperside 10 of the floor panel 1B.

The locking surfaces 41-42 define a maximally inclined tangent line R,which forms an angle A of at most 85 degrees with a straight lineparallel to the installation plane, wherein the tangent line R extendstowards the upper side 10, in distal direction in respect to thereceiving hook 14. Here, the angle A is equal to approximately 75degrees.

The bridge part 37 also defines a support surface 45, which here moreparticularly is made horizontal. In the coupled condition of the floorpanels 1A-1B, the locking part 16 rests on this support surface 45. Thesupport surface also serves as a reference.

It is advantageous that this support surface 45 is situated in that zoneof the bridge part 37 which is made rigid/thicker and moreover little ornot at all experiences the elastic bending of the lip 17. So, thissupport surface 45, which also functions as a reference, always can bewell defined.

FIG. 6 represents a step in the coupling movement of the edges 2-3 ofthe floor panels 1A-1B from FIG. 1.

As represented, the coupling parts 4-5 are configured such that at leasta portion of the locking part 16 fits in an opening 36 defined betweenthe locking part 18 and the proximal side 23 of the receiving hook 14,without having to elastically bend the lip 17 for this purpose.

In other words, the hook-shaped parts 13-14, in the step represented inFIG. 6, already are situated in a partially engaged condition of thehooks 13-14, without the lip 17 being elastically bent for this purpose.From this partially engaged condition, the elastic bending of the lip 17then can be initiated, in particular by pressing the locking hook 13,from the position represented in FIG. 6, further downward.

It is clear that the bending of the lip 17 here then is initiated by amutual interaction of the proximal sides 24-25 of the locking parts 16and 18.

FIG. 7 represents how the floor panels 1A-1B, starting from the coupledcondition, can be uncoupled.

The coupling parts 4-5 are configured such that they allow uncouplingthe floor panels 1A-1B, starting from the coupled condition, by means ofa rotational movement W1 of the one floor panel 1A around the otherfloor panel 1B, around an axis parallel to the installation plane andthe edges 2-3. In this rotational movement W1 the upper sides 10 of thefloor panels 1A-1B are moved towards each other.

As illustrated in FIG. 7, the rotational movement W1 can be combinedwith an elastic bending of the lip 17 of the receiving hook 14.

FIGS. 8 through 11 show more alternatives of the embodiment of the edges2-3 of the short sides of the floor panels 1A-1B from FIG. 1.

FIG. 8 represents that the lip 17 of the receiving hook 14 can beprovided with an elasticity groove 44 in order to increase theelasticity of the lip 17.

The elasticity groove 44 here is provided in a lower side of the lip 17and extends in distal direction up to the distal end of the lip 17. Inproximal direction, the groove 44 more particularly extends to beyondthe locking surfaces 41-42 of the locking parts 16 and 18.

It is noted that, as already mentioned herein above, the lower side ofthe lip 17 preferably is free from grooves or recesses, in order toguarantee the strength of the lip 17.

FIG. 9 shows that the elasticity groove 44 can be provided in a proximalside 23 of the receiving hook. The groove 44 then extends moreparticularly into the core of the floor panel 1B.

It is also noted that the groove 44, provided in the proximal side 23,prolongs the actual length of the lip 17.

FIG. 10 represents an alternative insertion piece 19, which insertionpiece 19 is known as such from the herein above-mentioned WO '893. Here,this relates to a displaceable tongue, which is provided in adisplacement groove.

Although the insertion piece 19 here is provided in a groove present inthe distal side 21 of the locking hook 13, according to an alternativethe insertion piece 19 can be provided in a groove present in theproximal side 23 of the receiving hook 14. In that case, it can beadvantageous to make the displacement groove inclined, such that theinsertion piece 19 becomes seated inclined in the floor panel 1B.

FIG. 11 represents that the locking elements 19-20 can be manufacturedfrom the material of the core 12 of the floor panels 1A-1B, and in onepiece therewith. Here, the locking in the direction V perpendicular tothe installation plane thus is effected without the assistance of aseparate insertion piece or insert.

Herein, the locking element 19 is made as a protrusion at the distalside 21 of the locking hook 13, whereas the locking element 20 is madeas an undercut at the proximal side 23 of the receiving hook 14.However, the reverse is possible, too, wherein the locking element 19 ismade as an undercut and the locking element 20 as a protrusion.

It is also noted that the floor panels 1A-1B, at their short and/or longsides, can be provided with a so-called bevel or chamfer at the upperedges, as is known as such from WO 01/96688 A1. Such bevel canfacilitate the installation of the floor panels even more.

It is also noted that it can be advantageous to provide the couplededges with a sealing, for example, at the proximal side 23 of thereceiving hook 14 and/or at the distal side 21 of the locking hook 13.Such sealing can further reduce or even completely exclude the risk ofpenetration of moisture or dust.

It is also noted that, although not represented, for the separateinsertion pieces 19 use can also be made of inserts which are used inso-called “side-push” systems, which as such are well-known in the art.

It is also noted that the dimensions mentioned in the presentdescription, such as lengths and thicknesses, have to be interpreted inthe not-coupled condition of the floor panels, if not stated otherwise.

The present invention is in no way limited to the herein above-describedembodiments, on the contrary, such methods, floor panels and carriermaterial can be realized according to various variants, without leavingthe scope of the present invention.

1. A set of floor panels for forming a floor covering, which comprisesat least two floor panels, which each comprise an upper side, a lowerside, and a core extending between the upper and lower sides, and whicheach comprise an edge provided with a coupling part and the coreextending from the edge to an opposite edge to said edge, wherein thecoupling parts are configured such that they allow realizing a coupledcondition between the floor panels by means of a substantially straightcoupling movement of the one floor panel in respect to the other floorpanel, according to a direction substantially perpendicular to aninstallation plane; wherein the coupling parts in the coupled conditioneffect a locking in the direction parallel to the installation plane andperpendicular to said edges, as well as a locking in the directionperpendicular to the installation plane; wherein the coupling part ofthe one floor panel is made as a hook-shaped part directed towards thelower side of the floor panel, herein below denominated locking hook,and the coupling part of the other floor panel is made as a hook-shapedpart directed towards the upper side of the floor panel, herein belowdenominated receiving hook; wherein the hook-shaped parts aremanufactured from the material of the core of the floor panels and aremade in one piece therewith; wherein the locking hook comprises a lipwhich is provided with a locking part extending towards the lower sideof the floor panel, and the receiving hook comprises a lip which isprovided with a locking part extending towards the upper side of thefloor panel; wherein the locking parts, in the coupled condition,cooperate in such a manner that they effect at least the aforementionedlocking in the direction parallel to the installation plane andperpendicular to said edges; wherein the coupling parts are configuredsuch that they, in the coupled condition, realize a tensioning forcepressing the coupled edges towards each other, by means of an elasticbending of the lip of the receiving hook; and wherein the lip of thereceiving hook, in the coupled condition, in the direction perpendicularto the installation plane, has a maximum bending of at most 0.0625 timesthe overall thickness of the floor panel; wherein the locking in thedirection perpendicular to the installation plane, at the edges to whichthe hook-shaped parts belong, is effected by means of locking elements,of which at least one locking element is made as a separate insert fromthe one and other floor panel.
 2. The set of floor panels of claim 1,wherein the insert is provided in a groove present in a distal side ofthe locking hook.
 3. The set of floor panels of claim 1, wherein theinsert has an attachment part provided in a groove in the edge of thepanel, the insert also having a movable part connected to the attachmentpart by a connection part and arranged to elastically move relative tothe attachment part and into a groove defined by a side of the otherfloor panel.
 4. The set of floor panels of claim 1, wherein the elasticbending of the lip of the receiving hook can be initiated by a mutualinteraction of proximal sides, including locking surfaces of the lockingparts.
 5. The set of floor panels of claim 1, wherein the lip of thereceiving hook comprises a bridge part connected to the core of thefloor panel, and an end part connected to the bridge part, to which endpart the locking part extending towards the upper side of the floorpanel is pertaining, wherein the bridge part comprises an upper sideprovided with a recess or groove, which recess, viewed according to thedirection parallel to the upper or lower side of the floor panel andperpendicular to the edge, is situated at a first distance from there,where the bridge part is connected to the core of the floor panel, andat a second distance from there, where the bridge part is connected tothe end part.
 6. The set of floor panels of claim 5, wherein the lip ofthe receiving hook shows its minimum thickness there, where said recessis provided.
 7. The set of floor panels of claim 5, wherein the bridgepart, there, where it is connected to the core of the floor panel, andthere, where it is connected to the end part, is made more rigid orthicker than there, where said recess is provided.
 8. The set of floorpanels of claim 5, wherein the bridge part comprises one or more of thefollowing characteristics: there, where the bridge part is connected tothe core of the floor panel, it has a thickness which is at least ⅕times the overall thickness of the floor panel; and/or there, where thebridge part is connected to the end part, it has a thickness which is atleast ⅕ times the overall thickness of the floor panel.
 9. The set offloor panels of claim 1, wherein the coupling parts are configured suchthat they allow uncoupling the floor panels, starting from the coupledcondition, by means of a rotational movement of the one floor panelaround the other floor panel, around an axis parallel to theinstallation plane and the edges, wherein during said rotationalmovement the upper sides of the floor panels are moved towards eachother.
 10. The set of floor panels of claim 1, wherein each of the floorpanels comprises an edge adjacent to its aforementioned edge, hereinbelow denominated adjacent edge, which is provided with a coupling part,wherein the coupling parts at the adjacent edges are configured suchthat they allow realizing a coupled condition between the floor panels,wherein the coupling parts at the adjacent edges, in the coupledcondition, effect a locking in the direction parallel to theinstallation plane and perpendicular to the adjacent edges, as well as alocking in the direction perpendicular to the installation plane, andwherein the coupling parts at the adjacent edges are configured suchthat they, in the coupled condition, realize a tensioning force pressingthe adjacent coupled edges towards each other, by means of an elasticbending of a lip pertaining to the coupling parts of the adjacent edges;and wherein, in the coupled condition of a plurality of the floorpanels, the average degree of bending of the lip of the receiving hook,viewed over a length of the coupled edges, differs from the averagedegree of bending of the lip pertaining to the coupling parts of theadjacent edges, viewed over a length of the coupled adjacent edges;wherein the coupling parts at the adjacent edges are realized as atongue and a groove, wherein the groove is bordered by an upper lip andthe aforementioned lip belonging to the coupling parts of the adjacentedges, herein below denominated lower lip; wherein the lower lip extendsbeyond the distal extremity of the upper lip; and wherein the tongue andthe groove are provided with lock-up parts, which in the coupledcondition effect said locking in the direction parallel to theinstallation plane and perpendicular to the adjacent edges; wherein thecoupling parts at the adjacent edges are configured such that they allowrealizing a coupled condition between the floor panels, by means of arotational movement of the one floor panel in respect to the other floorpanel, according to a direction parallel to the installation plane andthe adjacent edges, in such a manner that a plurality of the floorpanels can be coupled by means of a fold-down movement.
 11. The set offloor panels of claim 10, wherein the average degree of bending of thelip of the receiving hook is larger than the average degree of bendingof the lip pertaining to the coupling parts of the adjacent edges. 12.The set of floor panels of claim 1, wherein the lip of the receivinghook comprises a bridge part connected to the core of the floor paneland an end part connected to the bridge part to which the locking partextending towards the upper side of the floor panel pertains and whereinthe bridge part comprises an upper side provided with a recess and has afirst and second thickness at respective opposed sides of the recessbeing larger than a third thickness of the bridge part at the recess.13. The set of floor panels of claim 1, wherein said maximum bending isat most 0.05 times the overall thickness of the floor panel.
 14. The setof floor panels of claim 1, wherein the elastic bending relates to adownward bending, wherein the lip of the receiving hook partially issituated lower than a level defined by the lower side of the floor panelto which the locking hook is belonging; wherein the elastic bending indistal direction in respect to the receiving hook relates to acontinuously increasing bending, wherein said maximum bending occurs atthe distal end of the lip of the receiving hook; and wherein the lip ofthe receiving hook is bent at least over 25% of the length thereof. 15.A set of floor panels for forming a floor covering, which comprises atleast two floor panels, which each comprise an upper side, a lower side,and a core extending between the upper and lower sides, and which eachcomprise an edge provided with a coupling part and the core extendingfrom the edge to an opposite edge to said edge, wherein the couplingparts are configured such that they allow realizing a coupled conditionbetween the floor panels by means of a substantially straight couplingmovement of the one floor panel in respect to the other floor panel,according to a direction substantially perpendicular to an installationplane; wherein the coupling parts in the coupled condition effect alocking in the direction parallel to the installation plane andperpendicular to said edges, as well as a locking in the directionperpendicular to the installation plane; wherein the coupling part ofthe one floor panel is made as a hook-shaped part directed towards thelower side of the floor panel, herein below denominated locking hook,and the coupling part of the other floor panel is made as a hook-shapedpart directed towards the upper side of the floor panel, herein belowdenominated receiving hook; wherein the hook-shaped parts aremanufactured from the material of the core of the floor panels and aremade in one piece therewith; wherein the locking hook comprises a lipwhich is provided with a locking part extending towards the lower sideof the floor panel, and the receiving hook comprises a lip which isprovided with a locking part extending towards the upper side of thefloor panel; wherein the locking parts, in the coupled condition,cooperate in such a manner that they effect at least the aforementionedlocking in the direction parallel to the installation plane andperpendicular to said edges; wherein the coupling parts are configuredsuch that they, in the coupled condition, realize a tensioning forcepressing the coupled edges towards each other, by means of an elasticbending of the lip of the receiving hook; and wherein the coupling partsare configured such that at least a portion of the locking partextending towards the lower side of the floor panel fits into an openingdefined between the locking part extending towards the upper side of thefloor panel and a proximal side of the receiving hook, without having toelastically bend the lip of the receiving hook for this purpose; whereinthe locking in the direction perpendicular to the installation plane, atthe edges to which the hook-shaped parts belong, is effected by means oflocking elements, of which at least one locking element is made as aseparate insert from the one and other floor panel; wherein the elasticbending of the lip of the receiving hook can be initiated by a mutualinteraction of proximal sides, including locking surfaces of the lockingparts.
 16. The set of floor panels of claim 15, wherein the elasticbending of the lip of the receiving hook can be initiated from analready partially engaged condition of the hook-shaped parts.
 17. Theset of floor panels of claim 15, wherein the lip of the receiving hookcomprises a bridge part connected to the core of the floor panel, and anend part connected to the bridge part, to which end part the lockingpart extending towards the upper side of the floor panel is pertaining,wherein the bridge part comprises an upper side provided with a recessor groove, which recess, viewed according to the direction parallel tothe upper or lower side of the floor panel and perpendicular to theedge, is situated at a first distance from there, where the bridge partis connected to the core of the floor panel, and at a second distancefrom there, where the bridge part is connected to the end part; whereinthe lip of the receiving hook shows its minimum thickness there, wheresaid recess is provided; wherein the bridge part, there, where it isconnected to the core of the floor panel, and there, where it isconnected to the end part, is made more rigid or thicker than there,where said recess is provided.
 18. A set of floor panels for forming afloor covering, which comprises at least two floor panels, which eachcomprise an upper side, a lower side, and a core extending between theupper and lower sides, and which each comprise an edge provided with acoupling part and the core extending from the edge to an opposite edgeto said edge, wherein the coupling parts are configured such that theyallow realizing a coupled condition between the floor panels by means ofa substantially straight coupling movement of the one floor panel inrespect to the other floor panel, according to a direction substantiallyperpendicular to an installation plane; wherein the coupling parts inthe coupled condition effect a locking in the direction parallel to theinstallation plane and perpendicular to said edges, as well as a lockingin the direction perpendicular to the installation plane; wherein thecoupling part of the one floor panel is made as a hook-shaped partdirected towards the lower side of the floor panel, herein belowdenominated locking hook, and the coupling part of the other floor panelis made as a hook-shaped part directed towards the upper side of thefloor panel, herein below denominated receiving hook; wherein thehook-shaped parts are manufactured from the material of the core of thefloor panels and are made in one piece therewith; wherein the lockinghook comprises a lip which is provided with a locking part extendingtowards the lower side of the floor panel, and the receiving hookcomprises a lip which is provided with a locking part extending towardsthe upper side of the floor panel; wherein the locking parts, in thecoupled condition, cooperate in such a manner that they effect at leastthe aforementioned locking in the direction parallel to the installationplane and perpendicular to said edges; wherein the coupling parts areconfigured such that they, in the coupled condition, realize atensioning force pressing the coupled edges towards each other, by meansof an elastic bending of the lip of the receiving hook; wherein the lipof the receiving hook has a minimum thickness, which is at least ⅕ timesand at most ⅓ times the overall thickness of the floor panel; andwherein a length of the lip of the receiving hook, measured between avertical closing surface and the distal end of the lip of the receivinghook, is at least 1 time and at most 3/2 times the overall thickness ofthe floor panel; wherein the locking in the direction perpendicular tothe installation plane, at the edges to which the hook-shaped partsbelong, is effected by means of locking elements, of which at least onelocking element is made as a separate insert from the one and otherfloor panel.
 19. The set of floor panels of claim 18, wherein saidminimum thickness is at most 0.3 times the overall thickness of thefloor panel; and wherein said length is at most 1.4 times the overallthickness of the floor panel.
 20. The set of floor panels of claim 18,wherein the lip of the receiving hook comprises a bridge part connectedto the core of the floor panel, and an end part connected to the bridgepart, to which end part the locking part extending towards the upperside of the floor panel is pertaining, wherein the bridge part comprisesan upper side provided with a recess or groove, which recess, viewedaccording to the direction parallel to the upper or lower side of thefloor panel and perpendicular to the edge, is situated at a firstdistance from there, where the bridge part is connected to the core ofthe floor panel, and at a second distance from there, where the bridgepart is connected to the end part; wherein the lip of the receiving hookshows its minimum thickness there, where said recess is provided;wherein the bridge part, there, where it is connected to the core of thefloor panel, and there, where it is connected to the end part, is mademore rigid or thicker than there, where said recess is provided.